Grinding wheel feed mechanism



Oct. 25, 1949.

H. E. BALSIGER ET AL 2,486,244

GRINDING WHEEL FEED MECHANISM Filed Feb. 21, 1946 3 Sheets-Sheet l )7 4 44/ ATfORh/EY Oct. 25, 1949. BALS;GER ETNAL 2,486,244

GRINDING WHEEL FEED MECHANISM Filed Feb. 21, 1946 5 Sheets-Sheet 2 IN VE N TOR f/AROLD E. BALs/qER BY RALPH E. PRICE Patented Oct. 25, 1949 UNITED STATES PATENT OFFICE GRINDING WHEEL FEED MECHANISM Harold E. Balsigerand Ralp E. Brice, Waynesbore, Pa... assignors. to. Landis. Tool Company,

Waynesboro, Ba.

Application February 21, 1946; Serial No. 649,262 9. Claims. (01. 51-2) after; the slide has reached the end of: its move-- ment.

This invention is concerned with. the: latter cOndition. Previous timer'controlsusedin this man.- ner'were intiated by a sizing: device which stopped. the feedand started the: timer. In this: case they sizing. device is not available and. other means must be utilized to start the timer atfthe end: of; the feed movement.

It is therefore an object of this invention to provide a timing mechanism and means for initie ating operation thereof afterthe feed. movement has stopped.

A further object is: to provide means. for retuming the slide to inoperative position after a predetermined interval. of rest. in working position.

A further object isto provide a timer control. valve operable in response to restriction of a fluid; jet.

A further object is to provide control of a machine, by utilizing the. reaction. resulting from. interference with a, jet of. fluid.

A. further object is to provide means for-hold ing; the timer in slide retracting position until the-start. and. stop valve has been shiftedto-inoperative position.

In the drawings:

Figure 1 is an: end elevation of a grinding ma chine.

Figure 2 is a plan view of the feed" mechanism partly in section.

Figure 3 is a diagram of the hydraulic system of which this invention is a, part.

The bed. of the machine is indicated by numeral 10, the grinding wheel support by numeral It.

This machine has been described in detail in the Briceet'al. Patents No. 2,335,356 granted November 30, 1943, and 2,313,479 granted March 1943.

Said. feed mechanism consists of a cylinder 21) inibedjlli and having a pistonZl slidably'mountedi therein. Piston rod 22 is. in. the formof a lead; screw having screw threads 23. Said threads:

mesh with a worm wheel. 24.. on. vertical. shaft which. is rotatably mounted-in wheel baseil and alternately through line $6 cylinder 20- and line it! to the rod ends or both.

2 actuated by means of a handwheel 26.. Move-- ment; of piston: 21. is transmitted through. threads 23 and Worm wheel 24: to efiect a. lateral movetment of shaft- 25 to move: wheel base H at a rapidrate to: operative position. Forward movement of: saidipistonis. limited by engagement of pistonrcd: 22 with. a, positive: stop 2T.

A slow feed movement of said base is efiected by rotating piston rod. 22;. Screw threads 23: rotating-"in: engagement with worm wheel. 24: cause said. worm wheel. to function: as a: nut. Since. the:

screw is. stationary in. the bed, the worm wheel and the base must move axially thereof. rotation of. rod' 22. is accomplished: by mounting thereon. an elongated pinion 40.. A piston 45,. slid'ably' mou-nted' in. cylinder 46. in bed Ill and movable transversely of rocl 22 has a piston. rod 41 on which are out. rack. teeth 48 for engaging pinion 40. Said pinion 40 is long enough that it can move through the complete stroke of piston 2 I and still remain inoperative engagement with rack teeth 48.

The stroke of'piston 45 and hence the amount of grinding feed may be varied by means of an adjusting screw 50 in cylinder" head 51. Said screw has a graduated" head 52 to enable the operator to adjust. the mechanism for the total. amount of feed or stock removal.

The: hydraulic system for actuating the above described feed mechanism consists of a pump 68' and. areliefvalve 6 I for relieving, excess pressure in the. system. Fluid under pressure from said. pump is conducted through line 62 and a distributing line. 63 direct to.- the. head end of slow feedicylinder 46; A. throttle valve. 68. in said line. near saidv cylinder determines. the rate of the. grinding feed.

A branch 64 from line 63 pressure operated reversing valve 55. Said valve is held normallyin left hand 69. Said reversing valve. distributes said fluid to the headend of cylinders 20 and 46;. A. check valve 49 in passage 49' permits fluid to pass line 66;. Exhaust; fluid from is. carried'off through line 10.

Another? branch line said reversing: valve through line fil towithdrawwheei' base H it also supplies. fluid. to a position by aspring from cylinder 48': to

1-5: from line 63: supplies to as-tart and stop valve. it. A pivoted lever passes through line 80 to shift valve I6 and lever TI to the position shown in Figure 3.

In this position fluid is directed through a passage 85 and a check valve 86 in said passage to the head end of a cylinder 90 in which is mounted a piston 9I forming part of a timing valve 92. Another passage 93 having a throttle valve 99 connects said cylinder with the exhaust passage 10. In the dotted line position of lever 11, valve I6 is positioned to direct fluid through line I which divides into line IIII to valve 92 and line I02 to timer control valve H0.

In the inoperative position of valve 92 shown in Figure 3 said valve connects line IOI to line I05 which directs fluid to the left end of reversing valve 65.

A spring III holds valve left hand position shown. A line II5 connects valve IIO with the left end of timer valve 92 for the purpose of directing fluid to shift said val to the right.

Fluid from line 62 is also directed through line I and a restriction in the form of a coil I2I which permits a predetermined flow of fluid through line I22 to an outlet through which fluid passes in a jet directed against the end of piston rod 41. There is enough clearance around piston rod 41 to permit the escape of said fluid. A branch I25 from line I22 leads to the left end of timer control valve IIO so that any increase in 2.

pressure resulting from interference with said jet is exerted against the valve IIO to shift it to the right against spring I I I.

A line I connects line 61 with valve I I0. Said valve when in normal position connects line I30 with line H5. An extension [SI of line I30 is connected to the right hand end of valve H0.

Operation line position and valve I6 is shifted to the right.

In this position valve I6 connects line I5 with line I09 and directs fluid through line IOI, valve 92 and line I05 to shift reversing valve 65 to the right against spring 69. In this position of the reversing valve fluid from line 63 passes through line 64 which is connected through valve 65 to line 66 and the head end of cylinder 20 to shift piston 2I and slide of wheel base I'I forward to operative position. This movement continues until piston rod 22 engages the positive stop 21. At the same time fluid from line 63 which has been passing through valve 68, cylinder 46 and check valve 49 and exhausted through line 66,

valve 65 and exhaust line I0 is caused to act on piston 95 due to the fact that line 66 has been changed to a pressure line by valve 65 and the fluid entering cylinder 46 can no longer escape. Piston 95 thus moves to the left to rotate piston rod 22 and screw 23 by means of rack teeth 48 and' pinion 40. Thus, even after rod 22 has engaged stop 21 movement of the wheel base continues due to the rotation of screw 23 in contact with worm wheel 24 which acts as a nut and moves together with the wheel base II relative to said screw 23.

Piston moves to the left until it interfers with the flow of fluid from line I22 which results in the building up of pressure in said line and also in line I25 leading to valve IIO. Said valve vis thus shifted to the right against spring III.

In this position valve IIO connects line I02 with line I I5 and causes timer valve 92 to move to the right at a rate determined by the setting ofthrottle valve 94 in exhaust passage 93. As valve H0 normally in the,-

92 moves to the right, it cuts off the flow of fluid from line IOI to line I05 and reversing valve and connects line I05 with exhaust passage I06. Valve 65 is then shifted to the left by spring 69 connecting line 66 with exhaust and pressure supply line 64 with line 61 leading to the rod ends of the two cylinders 20 and 46.

' Fluid under pressure entering the rod end of cylinder 20 acts through line I22 and line I25 against the end of valve I I0 and would ordinarily hold said valve in operative or right hand position. In order to permit said valve to be shifted to the left hand position by spring II I, said fluid in line 61 also acts through line I30 and line I3I to the right hand end of valve I I0 to balance the pressure exerted in the other end of said valve. With equal pressure at each end, the spring III is free to shift the valve to the left. In this position the supply of pressure from line I02 is blocked and thereafter valve IIO connects line I I5 with line I32 which in turn is connected to line I39. Pressure is thus maintained on the timer valve 92 until valve I6 is shifted to the left to connect line I00 with the exhaust passage 70 and thus make sure that when timer valve 92 is reset that there will be no pressure exerted through lines WI and I05 to shift reversing valve 65 to the right and thus cause accidental operation of the rapid feed mechanism. In the left hand position of valve I6 pressure line I5 is connected to line in which is located a check valve 06 to the head end of cylinder to move piston 9I to the left and thus reset timer valve 92.

When the reversing valve 65 is in the position shown the pressure line 61 also supplies fluid through line 80 to the right hand end of valve I6. Ordinarily, if said valve I6 failed to function properly at this time, fluid in line 93 which is higher than cylinder 90 would flow back into said cylinder and shift valve 92 to starting position in which position, because of the failure of valve I6 to function, line I00 would still be connected to the pressure supply and said pressure would be exerted through lines IOI and I05 to shift reversing valve 65 to operative position.

We claim:

1. In a machine tool a tool support, a work support, hydraulic means for effecting movement of one of said supports toward and from the other including a piston and cylinder, a timing mechanism for initiating one of said movements, a jet of fluid under pressure, means movablewith said piston for restricting said jet of fluid, means responsive to the restriction of said jet for initiating operation of said timing mechanism including a timing valve for controlling a supply of fluid under pressure for actuating said piston to separate said support and a pressure operated valve for directing fluid under pressure to actuate said timing valve.

2. A hydraulic feed mechanism including a slide, a piston and cylinder for moving said slide toward and from operative position, a reversing valve normally in position to direct fluid under pressure to move said slide toward inoperative position, a jet of fluid under pressure directed against a part of said slide moving mechanism, said jet being restricted as said slide approaches final operative position, a conduit from said fluid supply having a restriction therein for maintaining pressure in the system while supplying fluid for said jet, a connection from said conduit between said jet outlet and said restriction to said timing control valve for shifting said valve in response to increase in pressure as said slide approaches said final operative position, said timing control valve being thus positioned to direct fluid to initiate operation of said timing valve, means for controlling the rate of movement of said timing valve, said timing valve being operable after a predetermined interval to permit the reversing valve to return to normal position and cause said slide to be retracted and said start and stop valve to be reset, said start and stop valve being effective in reset position to direct fluid to reset said timing valve.

3. In a grinding machine, a grinding wheel support, a work support, hydraulic means for effecting relative movement of one of said supports toward and from operative position including a piston and cylinder, a jet of fluid in the path of one of said moving parts, a timing mechanism for initiating movement of said support away from said operative position after a predetermined interval, said jet of fluid being restricted at a predetermined point in said movement toward operative position and means responsive to the restriction of said jet for initiating operation of said timing mechanism.

4. In a machine tool, a tool support, a work support, means for efiecting movement of one of said supports toward and from the other including a feed screw, a hydraulic motor operable through a rack and pinion for rotating said feed screw, a jet of fluid under pressure directed against the end of said rack, said rack being operable to restrict said jet, a timing mechanism for controlling the withdrawal of said support, and means responsive to restriction of said jet to initiate operation of said timing mechanism.

5. In a grinding machine, a grinding wheel support, a work support, means for eiTecting movement of one of said supports toward and from the other including a feed screw, power means for rotating said feed screw, a timing mechanism for controlling withdrawal of said support and means operable by said power means to initiate operation of said timing mechanism.

6. 'In a machine tool, a tool support, a work support, means for efiecting movement of one of said supports toward and from the other including a feed screw, a hydraulic motor for rotating said feed screw, a timing mechanism for controlling withdrawals of said support and means operable in response to movement of said motor to initiate operation of said timing mechanism.

7. In a machine tool, a tool support, a work support, hydraulic means for effecting relative transverse movement between said supports, in-

cluding a piston and cylinder, a start and stop valve for controlling operation of said piston and cylinder and a reversing valve, plus, a hydraulic timing mechanism for initiating a movement of one of said supports away from the other including a timing valve and a timer control valve, means operable when said piston reaches the end of its stroke in moving one of said supports toward the other for shifting said timer control valve to direct fluid under pressure to move said timing valve through its timing cycle and thus determine the duration of the interval during which said supports are held in operative relation, said timer being operable after said predetermined interval to cause said reversing valve to direct fluid under pressure to said piston and cylinder to separate said supports, reversing of said piston being erfective to permit resetting of said timing control valve, said reversing valve also directing fluid to reset said start and stop valve, and said start and stop valve when reset, directing fluid to reset said timing valve.

8. In a grinding machine, a grinding wheel support, a work support, hydraulic means for effecting relative movement of one of said supports toward and from operative position, including a piston and cylinder, a jet of fluid in the path of one of said moving parts, a common supply of fluid under pressure for said hydraulic means and said jet, a mechanism for initiating movement of said support away from said operative position, said jet of fluid being restricted at a predetermined point in said movement toward operative position, and means responsive to the change in pressure due to said restriction of said jet for initiating operation of said mechanism.

9. In a grinding machine, a grinding wheel support, a grinding wheel rotatably mounted thereon, a work support, hydraulic means for effecting relative movement of one of said supports toward and from operative position to perform a grinding operation including a piston and cylinder, a jet of fluid in the path of one of said moving parts, a supply of fluid under pressure for said hydraulic means and said jet, means for restricting the supply of fluid under pressure to said jet, and a mechanism operable in response to relative movement between said moving part and said jet of fluid for determining the progress of said grinding operation.

HAROLD E. BALSIGER.

RALPH E. PRICE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,082,728 Wood June 1, 1937 2,083,748 Steiner June 15, 1937 2,113,367 Belden et al Apr. 15, 1938 2,142,028 Herfurth Dec. 27, 1938 2,241,634 Decker May 13, 1 -1 

